Means and method for continuous dyeing of pile warp textiles, especially of carpets

ABSTRACT

To continuously dye pile textiles, such as carpets, the textile in the form of a continuously traveling length, is first impregnated with a wetting agent, the wetting agent is then squeezed from the textile as much as is possible, and the textile is then dyed.

United States Patent 1191 Appenzeller et a1.

1 1 Nov. 25, 1975 MEANS AND METHOD FOR CONTINUOUS DYEING OF PILE WARP TEXTILES, ESPECIALLY OF CARPETS [75] Inventors: Valentin Appenzeller, Kempen (Lower Rhine); Johannes Kutz, St. Tonis, Krefeld, both of Germany [73] Assignee: Eduard Kiisters Maschinenfabrik,

Krefeld, Germany Filed: Dec. 30, 1969 [21] App1.No.: 1,910

Related US. Application Data [62] Division of Ser. No. 650.450, June 30, l967. Pat. No.

[30] Foreign Application Priority Data Apr. 27. 1967 Germany 6214-1 [52] U.S. Cl. 8/17; 8/152; 68/22 [51] Int. Cl. D06P 5/00; DO6P 7/00 [58] Field of Search 8/17. 152; 68/202. 203. 68/22 [56] References Cited UNITED STATES. PATENTS 1.726.055 8/1929 Campbell 2.321.974 6/1943 Bird 3.271.102 9/1966 Vlorg 1n 8/9? Plillltll') Examiner-Thomas J. Herbert. Jr. Attorney. Agent, or Firm-Kenyon & Kenyon Reilly Carr & C hapin [57] ABSTRACT T0 continuously dye pile textiles, such as carpets, the textile in the form of a continuously traveling length, is first impregnated with a wetting agent, the wetting agent is then squeezed from the textile as much as is possible, and the textile is then dyed.

10 Claims, 5 Drawing Figures US. Patent Nov. 25, 1975 Sheet10f2 3,922,141-

US. Patent Nov. 25, 1975 Sheet 2 of 2 MEANS AND METHOD FOR CONTINUOUS DYEING OF PILE WARP TEXTILES, ESPECIALLY OF CARPETS CROSS-REFERENCES This application is a division of Ser. No. 650,450 filed June 30, 1967, by Valentin Appenzeller and Johannes Kutz now US. Pat. No. 3,541,815 issued on Nov. 24, 1970.

The present invention relates to a means and method for the continuous dyeing of pile textiles, especially of carpets, in which, after impregnation with a wetting agent, the liquid dye is applied to the material.

Recently, carpets with synthetic fibers and a binding or backing have been increasingly used as floor coverings.

Originally, dyed fibers were generally used for socalled tufting of carpets, especially for needle pile carpets. For a great number of reasons, such as storing of the dyed fibers and planning or process scheduling when using them for tufting, there have been attempts to dye finished carpets tufted with undyed fibers.

In this respect dyeing of carpets in winding vats has been used more and more in recent years. However, this way of dyeing is unsatisfactory, especially because winding vat dyeing is a discontinuous procedure and because some types of carpets such as those made of acrylic fibers and those with open piles which are not in the form of loops, cannot be dyed in the winding vat.

It has been attempted recently to dye carpets of all types in a continuous process. The problem of dyeing cut pile textiles by such method is, however, far more serious than continuous dyeing of textiles in general. The problem results from various properties of the carpet type in question which have to be observed when dyeing.

2 which has already delivered part of its dye contents to the breadth, whereby the dyeing vat contents is experiencing a reduction in dye concentration.

The same applies to any dye on an alkali basis where there is the same danger that the alkali concentration will gradually be reduced.

The average weight of the most usual carpets is about 1,000 glm Since, according to quality and desired pattern, for instance in difference dyeing, 100 to 300 and still more percent of dyeing fluid including corresponding chemical auxiliary agents must be applied, it will be necessary for reasons of economy to process by the aid of a minimum quantity of bath in any particular case. In this respect it is even desirable not to lead the binding or the backing of the carpet unnecessarily with dyeing fluid because the binding portion may amount to 40 percent of the total weight of some carpet qualities.

Another requirement which is absolutely necessary for the dyeing of carpets, is uniform dyeing all over the entire breadth. This requirement can only be complied with under certain conditions.

Other difficulties arise from the manifold types of carpets which are by now on the market. The pile sur- When dyeing carpets, for instance, the pile of the fin- 1 ished product should not be squeezed but must be open. The pile must be uniformly dyed down to the binding. With the dyeing methods which are known it is frequently likely to happen that the outer surface of the pile appears in the desired intensity of color or in the desired shade, while, however, there is no uniform dyeing of the pile down to the binding at the jute back, the pile showing a lighter shade towards its root. Vice versa the pile tips may have a lighter color whereas the root has a deeper one. This is known as the frosting effect.

Several kinds of carpets and more particularly carpets manufactured from staple fibers are liable to carry an extremely high amount of loose threads, a fact which requires attention when dyeing. The thread ends get into the dye bath and will block pumps and feed pipes within no time at all. Sometimes thread ends will accumulate in the bath vat and stick to the carpet surface in various layers rendering the carpets useless since lighter spots of the carpet will turn out below such accumulated thread ends.

During dyeing extraction of the dyeing agents from the dye bath will have to be avoided. In case extraction of the dyeing agent occurs, for instance when padding of the dye liquid onto the carpet within a padder, the extraction may result in the first applied color shade being darker than that at the end of the breadth, the reason being that on the way from soaking in the dyeing liquid and going towards the roll nip of the padder excess dyeing fluid is returning to the dyeing liquid vat,

face of some carpets has a pronounced pattern in the form of high and low pile. The variations in height within the individual pile areas may, for instance, range between 3mm and 15 mm. When such carpets are dyed, perfect dyeing all through the pile is extremely difficult to obtain. Another special problem in this connection is the removal of air included below the dye film.

At present difference dyed carpets are conquering an increasing market position. These carpets include various amounts of modified fibers which are tufted in a predetermined pattern. The fibers have been modified such that their dye acceptability differs very much. When these differently modified fibers are dyed, they will retain more or less dye, the final result after dyeing being a carpet pile with a color pattern.

When these carpets are dyed, it will be necessary to apply to the entire carpet surface a large excess of dye bath so that the fibers which have been modified to be particularly susceptible, are able to extract sufficient dye from their surroundings. Generally, this method is based on a bath quota of between 300 and 500 percent with respect to the original weight of the dry material. By special measures only a liquid load of this order may be balanced'on the carpet. With this method obtaining of a uniform color throughout the breadth is rather difficult.

A great number of tests, suggestions, and recommendations have been made to arrive at a solution in the total field of continuous dyeing of carpets which, on the one hand, does justice to carpet variations and which, on the other hand, defeats the problems outlined above.

The simplest method of continuous carpet dyeing is the padding of the dye liquid in a padder. But this method will only be possible for some dyeings and for comparatively light carpets having a small amount of thread ends. Padder dyeing involves the risk of the dyeing agent being extracted from the bath resulting in end non-uniformity of the dyed piece.

According to another suggestion carpet dyeing is to be effected such that first a liquid wetting agent is sprayed on, excess wetting agent being removed by a batter, and subsequently liquid dyeing agents are 3 sprayed on, their excess also being removed by vibration.

Apart from imperfect proportioning liable to occur with this method it is hardly possible in practice to cover carpets of large widths such as 5 m, uniformly with sprayed dye.

Similar tests have already also been made with the so-called pouring heads to which the dye bath is fed under pressure. Even in this case the risk that the bath is not uniformly penetrating down to the binding, i.e., dyeing all through the entire pile, involves considerable problems.

In order to guarantee a proportioned dye application the so-called dye application rolls have been developed. At least one of these rolls has been provided with a honeycomb rubber cover and a definite amount of dye fluid is fed to the honeycombs, or the dye application roll is expected to apply the dye to the carpet pile from a controlled bath level. Naturally, with this method the dye can only be applied to the carpet pile from below. The carpet, therefore, is passing via an upper roll functioning as a press roll pressing the carpet against the lower proportioning or application roll.

In this case the most serious problem is exact proportioning. But the principal drawback is the necessity to apply the dye to the carpet from below. It will not be possible to apply any high order amount of dye to the carpet. The amount of dye which can be applied is merely as great as corresponds to the saturation point of the pile fibers which are more or less close to each other. But in difference dyeing bath absorption of 300 to 500 percent of the dry weight of the material is required. A liquid load of this high order cannot be applied to the carpet from below since it exceeds by far the absorbing power of the carpet.

To avoid these drawbacks and to apply as great dye excess as possible means have become known which do not employ mechanical distribution of the dye bath. The carpet is merely passed through a bath vat provided with a return roll and drawn off upwards to enter the steamer. Part of the bath returns again down into the direction of the bath. The major part enters the steamer together with the carpet.

This process allows for difference dyeings. It is however unfavorable in that due to the backflow of the bath non-uniformities of the color are easily liable to occur. In addition, extraction of the dyeing agents from the bath cannot be prevented so that either end nonuniformity will occur or long first ends must be run until the bath has reached equilibrium again. It is also unfavorable in that, due to the fact that proportioning will not be possible, frequently such an excess amount of dyeing agents will be present on the carpet that it cannot be all taken up completely by the fibers. This results in comparatively high dyeing agent losses rendering the economical side of this method questionable.

The main object of the present invention is to provide a method and a means for the realization of the continuous dyeing method in which the problems outlined above will have been solved and the drawbacks experienced so far will have been eliminated, since by the invention dye absorption by the carpet is limited, as far as possible, to the pile to be dyed and furthermore measures are taken for uniform dyeing down to the bottom of the pile as well as to the entire length of the carpet without depending upon the absorbing power of the carpet. In addition bath application is effected corre- 4 sponding to the dyeing method involved which application may be continuously controlled between a desired minimum and maximum.

The problems outlined above have been solved according to the present invention by passing the tufted material or pile carpet following impregnation with the wetting agent, through a squeezer, thereby squeezing off and distributing the wetting agent. It is recommended to squeeze off the wetting agent as much as is possible by using the squeeze rolls of the squeezer. By squeezing off the wetting agent the same is distributed uniformly in the tufted material or carpet, increasing the absorbing power of the carpet uniformly. At the same time the binding or the backing which for reasons of economy is to be dyed as little as possible, is already comparatively saturated with liquid before the dyeing fluid is applied, at least as compared to its dry state.

Preferably a padding auxiliary agent is added to the wetting agent in the same proportional percentage as it will also be added to the actual dyeing fluid. In order to increase the viscosity a minor amount of thickening agents may also be added to the wetting fluid which thickeners approximately correspond in their composition to those later to be added to the dyeing fluid to be applied.

It may even be practical to add a minor amount of dyeing liquid to the wetting agent.

According to the present invention dye application following squeezing off may be effected such that the dye liquid is taken up by a roll immersing into a trough containing the dye liquid and rotating at a continuously controllable speed, stripped off by means of a doctor blade or scraper from the roll before the roll enters again into the trough, passed down via the scraper, and poured onto the pile face of the breadth passed below the scraper, in the form of a uniform, continuous dye film the width of which is controllable.

It is a special advantage in this respect that the liquid taken up by the rolls immersing into the bath according to the predetermined roll speed, is removed from the roll by the scraper and passed on to the surface of the breadth so that the nature and condition of the breadth does not have any influence on the quantity of the liq uid applied. The quantity of the liquid removed from the roll remains always the same because the liquid is stripped off from the roll before the roll again enters the bath. It is furthermore favorable in that, according to the desired dyeing method, exact proportioning of dye application may be effected by correspondingly controlling the rotating speed of the roll.

The dyeing agent applied needs a certain time of contact according to the strength applied to enter into the surface of the carpet. When adequate time cannot be provided sinking of the dyeing liquid alone will not suffice if the dyeing liquid is to penetrate the carpet down to the root of the fibers and fiber loops of the tufting and dye the same completely as well as uniformly. The present invention, therefore, provides for a mechanical step following dye application causing the dyeing liquid to penetrate and enter the root of the fibers or down to the carpet backing and comprising substantially a step of pressing in the dyeing liquid.

For this purpose the breadth may be passed with its pile face below a pressure means in the form of a rake or comb. The comb spaces are preferably comparatively small, and may have a depth exceeding the pile height.

In particular, penetration ofthe dyeing liquid into the pile may be effected such that following application of the dyeing liquid to the pile face of the breadth the same is passed between rolls, the roll acting upon the pile face being a grooved or comb roll.

It is also possible to provide for a rake instead of the grooved roll, said rake having flow apertures for the dyeing liquid and softly pressing against the pile face, although a grooved roll is preferred.

Due to the circumferential roll grooves it is guaranteed that the dye amount applied will not accumulate in front of the roll, but will pass through the nip. Accumulation of dye in front of the roll must be avoided, for such accumulation and retaining of dyeing liquid would result in a steadily increasing dye bank as the breadth passes, which bank would make predetermined proportioning useless. In addition, accumulation would result in an extraction of dye particles and prevent uniform dyeing for the length of the material.

A means for the realization of the method according to the present invention provides for'a wetting agent unit, a pair of squeezing rolls following said unit, a subsequent dye applying unitapplying dye to the pile face of the breadth; this unit being in the form of a roll rotating and immersing into the dyeing liquid and at its side which is falling upon rotat io,n of the roll, having a scraper inclined towards the upper roll crown and contacting the total length of the roll or alength equalling the width of the materi'al breadth respectively, the breadth passing below said scraper and the dyeing liq uid flowing down to the breadth over the upper side of the scraper; and a combing meansfor pressing the dyeing liquid thus applied'into thepile. I

The wetting unit itself may consist of a basin or trough containing the wetting agent, the carpet being, for instance, passed into and from the basin or trough via a return roll and at the same time being soaked with the liquid. Said soaking may suffice for carpets which permit such processing because comparatively free from loose threads.

However, with respect .to carpets comprising a lot of loose threads, it is especially preferred to design the wetting means in the same. way as the dye applying means.

The speed of rotation of the -roll receiving the dyeing liquid is controllable,'in particular continuously.

Preferably with a view to difference dyeings which require large dye application and also dye liquids of comparatively low viscosity, it may be favorable to arrange several dye applying means in a sequence in order to be able, if necessary, to apply maximum quantitles of dyeing liquid.

In order to provide for dye applications of different quantities, such as minor application in one color dyeing and maximum application in difference dyeing, it will be favorable to employ a plurality of rolls having grooves of different sizes, of which one or the other may be used as required. When a major quantity of dye is applied, the roll having larger flow openings or grooves will be used; when a minor quantity of dye is applied, the roll having smaller flow openings or grooves will be used. The same applies if a scraper in the form of a comb has been provided.

It is favorable to provide the grooved or comb roll in the form of a roll having an elastic cover such as rubber. Also the scraper may be provided with a flexible cover.

Providing a floor covering such as a carpet with a pattern is very expensive. Measures must, therefore, be taken that in all cases reproduceablc dyeing values are known beforehand over the total width and length. According to the present invention such reproduceable values are provided by testing minor sections pre-patterns by means of an equipment exactly corresponding to the dyeing equipment described at a 1:1 scale, the only difference being that the width of said equipment is reduced to about 50 cm.

The speeds of the dye application rolls must be exactly readable both with the above pre-pattern equipment and with the actual dyeing equipment, since this will be decisive for proportioning of the dyeing liquid and consequently for reproduceability. In the same manner the wetting values must be able to be reproduced exactly and this not only with respect to squeeze roll pressure but also to roll hardness, roll diameter, and speed.

Following the dyeing step the breadth is subject to an adequate time of steam fixing, after which it will then be washed and dried.

Two embodiments of a means for the realization of the method according to the present invention are schematically illustrated by the accompanying drawings, in which:

FIG. 1 is an elevational view of a first embodiment according to the present invention.

FIG. 2 is an elevational view of a second embodiment according to the present invention.

FIG. 3 is a sectional view of a grooved comb r'oll.

FIG. 4 is a sectional view of a grooved comb roll having a rubber cover.

FIG. 5 is a sectional view of a scraper which may be used instead of a grooved roll.

In either embodiment the carpet has been identified by l. The tufted pile carpet passes a wetting station A, a squeezing station B, one or several dye applying stationsC as well-,as a dye penetrating station D, from which the carpet loops downwardly, the carpet being drawn off from this loop in the direction of the arrow E. The sag control of the loop has been defined as F.

With the embodiment according to FIG. 1 the wetting station has been provided with a roll 2 over which the carpet passes with its pile facing upwardly, a trough 3 containing the wetting fluid being positioned above the'carpet. Feeding of the wetting fluid is effected at 4. The roll 5 which is'rotating and driven by an appropriate drive, is immersing into said trough or the liquid contained therein respectively. The speed of the roll is continuously controllable. If desired, the liquid level within the trough may be controllable too. The direction of rotation of the roll has been marked by the arrow 6. The scraper or doctor blade contacts the roll 5 throughout its length and the breadth of carpet throughout its width at the side of the roll which is falling upon rotation of the roll receives the liquid taken along by the roll out of the trough and scraped off by the doctor blade 7 to fall onto the pile face of the carpet.

The thus wetted breadth next passes upwardly through squeezing rolls 8 at the squeezing station, which are practically provided as non-deflective rolls and more particularly as Swimming Rolls, already known. The pressure of the squeezing rolls may be controlled. non-deflective rolls made and sold under the trade name Swimming Rolls or the registered trademark Kusters Swimming Rolls incorporate the prin- 7 ciple of the Kusters US. Pat. No. 2,908,964. dated Oct.

The breadth leaving the squeezing rolls 8 at the squeezing station B passes over a roll and advances horizontally below the dye applying unit which, in FIG. I. has been designed in the same manner as the wetting equipment, comprising a trough 3, a feeding 4'. a roll 5' with its appropriate drive and the scraper or doctor blade 7, said roll immersing into a dye liquid 10 contained in the trough 3, and said scraper contacting the roll throughout its length, scraping off from the roll the dye liquid taken along by the roll out of the trough, and passing the dye liquid in the form of the solid flow as scraped from the roll onto the pile face of the carpet throughout its width. The direction of rotation of the roll has been marked by the arrow 6. The rotating speed of the roll 5 may be continuously controlled. In the same manner the liquid level to be maintained in the trough may be controlled.

A majority of dye applying means may be arranged in a sequence. In FIG. 1 a second dye applying equipment has been indicated.

The breadth leaving the dye applicator passes between the rolls 11 and 12 of which roll 11 which presses on the carpet pile is designed as a grooved roll. The grooves are comparatively close to each other. In the embodiment shown the width of the grooves is 1.5 mm and the distance between the grooves is also 1.5 mm. The depth of the grooves is 3 mm. The grooved roll may be replaced by another grooved roll with another groove dimension to satisfy all requirements. FIG. 3 is a sectional view of a groove d roll.

The grooved roll may'also be a roll having a rubber cover or a chemically resistant cover such as polytetrafluor ethylene, as may be seen in FIG. 4. The flexible cover has been identified by 13.

Instead ofa grooved or comb roll it may even be possible to provide a scraper 14 in the form of a comb a sectional view of which is shown in FIG. 5. Also the rake may be provided with a rubber cover or a similar one such as a polytetrafluor ethylene cover. The rake must be inclined towards the direction of the running breadth in which case the end contactingthe breadth is slightly bent off in the same direction because of its flexibility.

The breadth of carpet leaving the pair of rolls 1] and 12 is caused to sag in the form ofa loop 15 and is pulled off via a sag control from the same in the direction of the arrow E.

The difference between the embodiment according to FIG. 1 and that according to FIG. 2 is that, in FIG.

2, a trough 16 has been provided for wetting the breadth, said trough containing the wetting liquid 17. The carpet is passed through the wetting agent via the roll 18 and by means of the roll 19 located within the trough is immersed in the wetting agent.

What we claim is:

l. A tufted or pile textile continuous dyeing method including causing a length of said textile to travel continuously while applying a liquid wetting agent and thereafter a dyeing liquid to its pile; wherein the improvement comprises pressure squeezing said textile after applying liquid wetting agent and prior to applying dyeing liquid and under pressure squeezing conditions squeezing off and distributing said agent uniformly in said textile throughout the latter and increasing said textiles absorbing power uniformly.

2. The method of claim 1 in which said wetting agent is applied to said textile by completely immersing said textile in a body of said wetting agent.

3. The method of claim 1 in which said squeezing is effected by passing said textile between rolling surfaces which do not deflect under the squeezing pressure.

4. The method of claim 3 in which the pressure exerted by said surfaces on said textile squeezes off said agent substantially as much as is possible by using said surfaces.

5. The method of claim 1 in which said application of dyeing liquid is effected by causing said textile to travel substantially horizontally with its pile upwardly and said dyeing liquid is poured on said textiles pile in the form of a uniform continuous dyeing liquid film of uniform quantity and extending transversely for the width of said textile which is to be dyed.

6. The method of claim 5 in which said quantity is limited substantially to the dyeing liquid absorption of the pile of said textile.

7. The method of claim 6 in which said squeezing is effected by passing said textile between rolling surfaces which do not deflect under the squeezing pressure.

8. The method of claim 7 in which the pressure exerted by said surfaces on said textile squeezes off said agent substantially as much as is possible by using said surfaces.

9. The method of claim 8 in which said wetting agent is applied to said textile by completely immersing said textile in a body of said wetting agent.

10. The method of claim 6 in which after said application of dyeing liquid the pile of said textile is momentarily pressed backwardly and downwardly without forming a body of liquid in front of this pressing. 

1. A TUFTED OR PILE TEXTILE CONTINUOUS DYEING METHOD INCLUDING CAUSING A LENGTH OF SAID TEXTILE TO TRAVEL CONTINUOUSLY WHILE APPLYING A LIQUID WETTING AGENT AND THEREAFTER A DYEING LIQUID TO ITS PILE; WHEREIN THE IMPROVEMENT COMPRISES PRESSURE SQUEEZING SAID TEXTILE AFTER APPLYING LIQUID WETTING AGENT AND PRIOR TO APPLYING DYEING LIQUID AND UNDER PRESSURE SQUEEZING CONDITIONS SQUEEZING OFF AND DISTRIBUTING SAID AGENT UNIFORMLY IN SAID TEXTILE THROUGHOUT THE LATTER AND INCREASING SAID TEXTILE''S ABSORBING POWER UNIFORMLY.
 2. The method of claim 1 in which said wetting agent is applied to said textile by completely immersing said textile in a body of said wetting agent.
 3. The method of claim 1 in which said squeezing is effected by passing said textile between rolling surfaces which do not deflect under the squeezing pressure.
 4. The method of claim 3 in which the pressure exerted by said surfaces on said textile squeezes off said agent substantially as much as is possible by using said surfaces.
 5. The method of claim 1 in which said application of dyeing liquid is effected by causing said textile to travel substantially horizontally with its pile upwardly and said dyeing liquid is poured on said textile''s pile in the form of a uniform continuous dyeing liquid film of uniform quantity and extending transversely for the width of said textile which is to be dyed.
 6. The method of claim 5 in which said quantity is limited substantially to the dyeing liquid absorption of the pile of said textile.
 7. The method of claim 6 in which said squeezing is effected by passing said textile between rolling surfaces which do not deflect under the squeezing pressure.
 8. The method of claim 7 in which the pressure exerted by said surfaces on said textile squeezes off said agent substantially as much as is possible by using said surfaces.
 9. The method of claim 8 in which said wetting agent is applied to said textile by completely immersing said textile in a body of said wetting agent.
 10. The method of claim 6 in which after said application of dyeing liquid the pile of said textile is momentarily pressed backwardly and downwardly without forming a body of liquid in front of this pressing. 